A term used among Dragon Quest players where you leave at least one slime (or other monster) alive in a battle so that it will call for backup, allowing more monsters to appear to defeat, which will eventually give you immense amounts of exp. points if continued for long periods of time.

Person 1: Hey, a slime! I'm gonna do some slime spamming for a few hours!!!

Person 2: I'm just gonna fight a king metal slime and use 1/4 the effort.